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By Dr. Bukar Abba Zarami
Following the recent detection of Ebola Virus Disease (EVD) in Patrick Sawyer, a Consultant with the Liberian Finance Ministry who collapsed on arrival at the Murtala Mohammed International Airport, Lagos, on 20th July, 2014, public discourse has shifted with only the issues of the missing Chibok girls and the onslaught of so-called female bombers rivaling to that of EVD. After the case detection, the hospital to which he was admitted was immediately closed as a control measure to further mitigate the spread of the infection. A total of 70 people were identified and monitored as contact of the index case. At a press briefing immediately after the case detection, the Lagos State authorities and the Federal Ministry of Health assured Nigerians and called on them to be calm and not to panic saying that no Nigerian was infected with the virus yet. Many people are concerned about the possibility of a large scale epidemic in highly populated Lagos or other states in the country which would further compound the existing hardship the common man is suffering especially with the on-going Nigerian Medical Association (NMA) strike. A lot of questions were asked by Nigerians with the aim of understanding the dynamics of the infection, while other questions were borne out of distrust to the existing system that usually claims to be ‘on top of the situation’ only for a more devastating event to occur subsequently. Some examples of the questions raised include: “Why can’t Ebola virus infect all corrupt government officials during air travel to free the country from corruption?” “Does Nigeria have the capacity to handle Ebola outbreak?” “If I happen to travel along with an infected person on the same car, would I contract the disease?” “Could hot salt and water bath prevent the transmission of Ebola virus”? “Is it true that bitter Kola nut could treat EVD?” In Nigeria, whenever a situation arises, people always look to a simplistic or near impossible fantasy for solution. The funniest of all the questions was the one I heard coming from Boko Haram enclave, Borno State, that;
To buttress his point, the inquirer cited the recent chasing away of Boko Haram members from the Sambisa Forest by “supernatural” means including attack of members by snakes, scorpions and bees which he believes were due to prayers! These have been reported by a large cross-section of newspapers in the country at the onset of the rainy season. “Therefore, a similar attack by Ebola virus at Sambisa Forest will not be out of place”, he said. I am not an expert in EVD, however, with my background in International Health, I believe I can attempt to answer some of the questions raised. Although the social media has been saturated with messages and articles about EVD, notwithstanding, there is a need to further refresh our memories on EVD i.e. its characteristics, dynamics, treatment, epidemiology and control in order to address the questions raised in a proper context. According to the World Health Organisation (WHO) website and other sources, Ebola Virus Disease (EVD) or Ebola Hemorrhagic Fever (EHF) is a severe often fatal illness in humans caused by Ebola viruses with Case Fatality Rate (CFR) as high as 90%. This means up to 9 in 10 of people infected with the disease would die (depending on the epidemics). The current outbreak is the worst ever with over 961 deaths spanning across Liberia, Sierra Leone, Guinea and Nigeria. With reference to history, Ebola first appeared in 1976 in two simultaneous outbreaks, in Nzara, southern Sudan, and Yambuku in northern Democratic Republic of Congo. The latter was in a village situated near the Ebola River, from which the disease takes its name. The disease is first acquired by the human population when a person comes in contact with the blood or bodily fluids of an infected wild animal. Handling of several wild animals has been documented including infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead. However, fruit bats are believed to carry and spread the disease without being affected themselves; this has raised speculation that these mammals may play a role in maintaining the virus in the tropical forest. Once infection occurs in human beings, Ebola then spreads in the community through human-to-human transmission, with
Other means of transmission include during burial ceremonies in which mourners have direct contact with the body of an infected person. Men who were lucky to recover from the disease can still transmit the virus through their seminal fluid up to 61 days following recovery from the illness. Health-care workers are commonly infected while treating suspected or confirmed EVD patients through close contact without correct infection control precautions and adequate barrier nursing procedures. The usual Incubation Period is 8-10 days (rarely from 2 to 21 days). This is the period between contact with the virus and manifestation of sign and symptoms. Some infections could be transmitted from one person to another during the incubation period before the onset of symptoms; fortunately, Ebola patients are not contagious until they are acutely ill (we will later see the role of this in EVD control). Symptoms are characterised by sudden onset of fever, intense weakness, muscle pain, headache and sore throat. This is followed by vomiting, diarrhoea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding. Diagnosis requires high index of suspicion because the disease mimics the symptoms of malaria, hepatitis, typhoid fever, shigellosis, cholera, leptospirosis, plague, rickettsiosis, relapsing fever, meningitis, and other viral haemorrhagic fevers.
Definitive diagnosis is made in the laboratory through several types of tests: Antibody-capture Enzyme-linked immunosorbent Assay (ELISA), Antigen Detection Tests, Serum Neutralization Test, Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) Assay, Electron Microscopy and Virus isolation by cell culture. New developments in diagnostic techniques include non-invasive methods of diagnosis (testing saliva and urine samples) and testing inactivated samples to provide rapid laboratory diagnosis to support case management during outbreak control activities.
Like many other viral diseases, EVD has no treatment nor vaccine for prevention. Supportive treatment include giving the person either Oral Rehydration Therapy (ORT) or intravenous fluids. Treatment is primarily supportive in minimizing invasive procedures, balancing fluids and electrolyte to counter dehydration, administration of anticoagulants early in infection to prevent or control Disseminated Intravascular Coagulation (DIC) which is fatal, administration of pro-coagulants late in infection to control external and internal bleeding, maintaining oxygen levels, and administration of analgesics for pain, antibiotics or anti-mycotics to treat secondary infections. As outlined earlier, the disease has a high death rate: often between 50% and 90%. The current CFR is estimated at 60%.
Primary prevention i.e. prevention from the animal source to humans include reducing the risk of wildlife-to-human transmission from contact with infected fruit bats or monkeys/apes and the consumption of their raw meat. Gloves and other appropriate protective clothing should be used in handling wild animals. Animal products (blood and meat) should be thoroughly cooked before consumption.
Pig farms in Africa can play a role in the amplification of infection because of the presence of fruit bats on these farms. Routine cleaning and disinfection of pig or monkey farms with sodium hypochlorite (bleach) is effective in inactivating the virus. If an outbreak is suspected in a farmland, the premises should be quarantined immediately. Other measures to reduce further transmission include culling of infected animals, burial or incineration of carcasses, restricting or banning the movement of animals from infected farms and so on.
To reduce the spread of Ebola infection among people, raising awareness of the risk factors for Ebola infection and other individual protective measures should be instituted. Reducing the risk of human-to-human transmission in the community arising from direct or close contact with infected patients or their bodily fluids should also be instituted. Close physical contact with Ebola patients should be avoided. Regular hand washing with soap and other disinfectants where available is required after visiting patients in hospital, and also after taking care of patients at home.
Attending burial ceremonies is a major traditional rite in Africa, affected communities should be informed about the nature of the disease and its containment measures, including burial of the dead. People who have died from Ebola should be buried immediately and safely using recommended guidelines.
WHO has created a guide on standard precautions in health care practice. Standard precautions are recommended in the care and treatment of all patients regardless of their perceived or confirmed infectious status. These include the basic level of infection control—hand hygiene, use of personal protective equipment to avoid direct contact with blood and body fluids, prevention of needle stick and injuries from other sharp instruments, and a set of environmental controls. Tracing and following up people who may have been exposed to Ebola through close contact with patients are essential. Before answering the questions raised, we need to be conversant with some epidemiological concepts with regards to disease transmission. Some factors influencing the transmission of disease in general include; the infectiousness of the causative organism, duration of infectivity of affected patients and the number of people at risk in contact with the affected patient and the Basic Reproduction Number (Ro). Ro of a disease is the number of cases one case generates on average over the course of its infection period, in an otherwise uninfected population.
If the Ro is less than 1, epidemics will not be maintained (i.e. the disease will die out), and if Ro is greater than 1, the infection will spread in the population. It is difficult to calculate the exact value of Ro for different diseases; using data from several epidemics and mathematical models, the value of Ro is determined. For Ebola virus, Ro= 2.7 (1-4). This means on an average, Ebola is transmitted to about 3 people from an infected patient during its period of infectivity (i.e. before a patient dies or recovers). When compared to other viral diseases like measles, Ro ranges from 12-18! EVD creates more fear than any other disease because of the high case fatality rate.
Now back to our questions. Most of them were addressed during the course of our discussion, but I will dwell on Nigeria’s capacity to handle EVD and the possibility of an outbreak in Sambisa Forest. Does Nigeria have the capacity to handle Ebola outbreak? President, Academy of Science, Prof Oyewale Tomori while responding to the announcement of the outbreak as reported on the Nations Newspaper of 29th July, 2014 said;
At the onset of the outbreak, all precautionary measures to mitigate against the spread of the infection were instituted; 70 contacts (39 hospital, 22 airport and 9 laboratory) were identified and traced. The Minister for Health while having a meeting with the House of Representative Committee on Health said; “Mr Sawyer left Liberia for an ECOWAS meeting to be held in Nigeria. But before he left Liberia, he knew he was sick, and the government told him not to travel, but he ignored the directive and travelled for the meeting.” Similarly, video recording showed Tom sawyer to be terribly sick but he decided to travel against advice. Therefore, it is not surprising that he was able to infect 8 Nigerians with one death recorded; also being very sick, raised the chances of transmission.
While responding on the identified contacts and Nigeria’s capacity to handle the outbreak, Derek Gatherer, a virologist at Britain’s University of Lancaster said anyone on the plane near Sawyer could be in “pretty serious danger,” but relatively wealthy Nigeria, Africa’s most populous country, was better placed to tackle the outbreak than poorer neighbours. Nigeria have deep pockets and they can do as much as any western country could do if they have the motivation and organisation to get it done”, he said.
Similarly, Peter Piot, the Director of London School of Hygiene and Tropical Medicine and the discoverer of Ebola Virus said he wouldn’t be worried to sit next to someone with Ebola virus on the tube as long as they don’t vomit on you or something; it is an infection that requires very close contact. ”He went further to say that a “really bad” sense of panic and lack of trust in the authorities in West Africa had contributed to the world’s largest ever outbreak. Recent history in Liberia and Sierra Leone was complicating efforts to tackle the deadly virus which kills as many as nine-tenths of people infected. Let’s not forget that these countries are coming out of decades of war.”
Going by these discussions, it is obvious that Nigeria has the capacity to overcome the outbreak especially with the international support from WHO and other allied organisation and of course the political will from the Federal Government (evidenced by the recent declaration of Ebola as a National Emergency by the president). However, earlier statement by some government officials during an Ebola briefing few days after the outbreak that no Nigerian was infected with the virus was too pre-mature and uncalled for. Unfortunately, despite all the assurances (which is the normal thing to do during outbreaks), eight of the primary contacts were infected.
Can Ebola outbreak occur in Sambisa Forest? This is even more difficult to answer. Let’s assume an inhabitant of Sambisa Forest happened to travel on board the Monrovia-Lome and Lome-Lagos flight and the purported passenger was seated next to the infected Liberian. Travelling together to such a distance without contact with the bodily fluid of the infected Liberian means a minimal risk of transmission (the discoverer of the virus can happily sit next to an infected person on a train). Therefore, chances of transporting EVD to Sambisa Forest is really remote. But if such a person was vomited or bled upon, defies security odds and reached Sambisa Forest without being grounded by the disease (considering the closure of Maiduguri airport, very long road distance travel from Lagos to Maiduguri occasioned by multiple road blocks), then that could be considered as a possibility. Using the above analogy, EVD reaching Sambisa Forest through human-to-human transmission is near impossible. An easier way to achieve an outbreak is to consider a different route of transmission. Since Sambisa is a forest with rich wildlife; let’s assume that the specie of fruit bats are abundant and such bats are infected with Ebola virus (don’t know how that happens). An inhabitant of Sambisa Forest may decide to go out to hunt for “bush meat” (which is unlikely because it may not be considered Halal, but could not be ruled-out in a war situation) and could accidentally get infected. Going by the second analogy, the chances of transmission and outbreak (though very rare) through the latter seems more feasible.
Assuming such an outbreak occurred, Will that be the solution to the existing insurgency? Will the infection be contained at the forest? How about its potential spread to other neighbouring states surrounding Sambisa? The person praying for the outbreak to occur in Sambisa Forest will definitely not be spared too! I don’t want to think about the possibility of an outbreak in the North-East on top of the current insecurity, hunger, political instability, non-functioning health system, NMA strike, psychological trauma, and so on. No matter the level of distrust of current leadership that exists, people shouldn’t go to the extent of inviting Ebola virus to Sambisa Forest on top of our current situation. Although Boko Haram is deadly, EVD outbreak is never a solution to even the deadly Boko Haram.
“Could hot salt and water bath prevent the transmission of EVD?”, “Is it true that bitter kola nut could treat EVD?” I think these are the greatest jokes I have heard in years. To answer this, I will borrow a leaf from the response given by a senior colleague, that eating the right adrenal gland of a right handed pure bred chicken followed by warm saline bath at midnight and 3 pieces of bitter kola nut is a cure for EVD!
In another development, rumours had it that some health workers tendered their resignations following the designation of their hospitals as Ebola Reference Centres. Going by our discussion, it was very unfortunate that those 8 contacts were infected by the index patient. Being the first case, strict precautionary measures were not followed and the index patient was terribly sick (which resulted in higher transmission). I am not immune to EVD, but I will gladly accept the responsibility of heading an Ebola Response Team anywhere in the country!
To address the current challenges, the government should intensify on raising awareness about EVD through radio jingles, at motor parks and other public places. All 36 States and the FCT should each form an Ebola Response Team. The NMA has already set-up a committee to combat the spread of EVD in the country. NMA should also liaise with the State Ministry of Health (SMOH), WHO and Centre for Disease Control (CDC) at the State level. The SMOH should also establish a Viral Haemorrhagic Fever surveillance system. This system should not be just limited to case identification, but also appropriate reporting to the SMOH and the established Committee via the Monitoring and Evaluation unit. Sick passengers should be screened and isolated at the airports and other boarders.
A community based rapid awareness campaign through community and religious leaders will be invaluable. Messages on transmission and prevention should be delivered during Friday sermons in mosque and Sunday church services. At the hospitals, the SMOH should provide guidelines on EVD prevention and strict adherence to such protocols should be emphasized. The history of travel to Lagos State should also be included in such protocols. At individual level, people should wash their hands regularly with soap and water, minimize or avoid handshakes, or use hand sanitizers with at least 60% of alcohol.
Dr Bukar Abba Zarami. |
